The question assumes that the helicopter does not have a governor device, which helps maintain the rotor RPM within the defined operating limits each time the collective is raised or lowered by increasing or reducing the throttle. Thus, for this question, during the climb, as the Pilot raises the collective to gain altitude, he/she should manually increase the throttle at the same time.

“Loss of tail rotor effectiveness” → INCORRECT. It is a condition where the tail rotor fails to provide adequate thrust to counteract the torque produced by the main rotor, leading to an uncommanded yaw rate. This can result in a loss of directional control if not corrected promptly. Factors affecting LTE include high all-up mass (AUM), high power settings, low airspeed (typically less than 40 knots), and high density altitude (DA).

“Settling with power” → INCORRECT. Also known as vortex ring state, is a condition in helicopter flight where the aircraft descends into its own downwash, leading to a loss of lift. This occurs when the helicopter is in a vertical or near-vertical descent with low forward airspeed and high power applied. The rotor system becomes engulfed in a vortex ring, causing turbulent airflow and a significant reduction in lift. To recover from this state, the pilot must reduce the rate of descent and increase forward airspeed to exit the turbulent airflow.

“Overpitching” → CORRECT. If during climb, collective is raised without increasing the throttle, a situation will occur where more pitch angle will be applied to the rotor blades without having sufficient engine power to counteract the resulting increase in rotor drag. Engine power must, therefore, be increased to maintain rotor RPM when increasing total rotor thrust through the collective. The increased pitch angle will cause the blades to cone up leading to the rotor disc area reducing in size and the total rotor thrust will decrease. If the collective pitch is increased in such a situation, the main rotors will slow down and so will the tail rotor, leaving it to do more work with less power. If even more collective is applied, then drag will be furher increased without sufficient engine power and the situation will get even worse, leading to overpitching.

“Exceeding the maximum manifold pressure” → CORRECT. If the pilot raises the collective without increasing the throttle, the manifold pressure may be exceeded. This is because the increased collective pitch demands more power from the engine, and if the throttle is not adjusted accordingly, it can lead to an overboost condition where the manifold pressure exceeds its maximum limit. This can increase the risk of detonation and engine damage.